1. Field of the Invention
The present invention relates to a film end detecting device of a camera.
2. Related Background Art
Conventionally, a pre-wind type camera, which draws out an entire unexposed film from a loaded film cartridge, and rewinds it into the film cartridge in every photographing operation, is known. Also, a technique for recording various pieces of information on a magnetic recording medium coated on a film is already known (U.S. Pat. No. 4,864,332).
When pieces of information to be recorded on the magnetic recording medium are ones in units of photographing frames, if these pieces of information are not recorded at predetermined positions in units of photographing frames, recorded information may not often be reproduced in correspondence with the photographing frames. In the conventional pre-wind type camera, the first frame (a frame closest to the film end) is aligned while drawing out a film, and the second or subsequent frame is aligned while rewinding a film. For this reason, only the first frame is undesirably shifted from other frames.
The present applicant proposed a film feed control device of a camera, which had an object to precisely align the first frame with a predetermined photographing position (Japanese Patent Application Laid-Open No. 2-173998). With this device, the number of photographable frames of a film are memorized or stored in advance in a camera, and perforations of the film are detected in a pre-wind operation to count the number of fed frames of the film. Then, whether or not all the photographable frames are drawn out is detected based on the count result and the stored number of frames. If it is detected that all the photographable frames are drawn out, the film is further drawn out by a predetermined amount. Thereafter, the film is. rewound to align the first frame with the predetermined position. In this manner, the first frame can be precisely aligned.
A pre-wind type camera or normal wind type camera for winding a film frame by frame in every photographing operation detects a state wherein a film is completely drawn out and can no longer be fed to determine a film end, and the camera stops a film feeding motor.
However, in the device described in Japanese Patent Application Laid-Open No. 2-173998, the number of fed frames of a film is counted in a pre-wind operation, and whether or not all the photographable frames are drawn out is detected based on the count result and the stored number of photographable frames. For this reason, for example, if a battery is removed during the pre-wind operation, the count result disappears. Therefore, even if a new battery is loaded to continue the pre-wind operation, the first frame cannot be aligned with the predetermined position.
As described above, in a camera, which determines a film end when a film is completely drawn out and can no longer be fed, the film is temporarily forcibly pulled although it can no longer be fed. As a result, the film may often be undesirably stretched or broken.